Provide half floating point support as a storage only type.
Lack of half FP was a regression compared to llvm-gcc.

llvm-svn: 142016
diff --git a/clang/lib/Parse/ParseExpr.cpp b/clang/lib/Parse/ParseExpr.cpp
index 548a599..bc8bbf5 100644
--- a/clang/lib/Parse/ParseExpr.cpp
+++ b/clang/lib/Parse/ParseExpr.cpp
@@ -920,6 +920,7 @@
   case tok::kw___int64:
   case tok::kw_signed:
   case tok::kw_unsigned:
+  case tok::kw_half:
   case tok::kw_float:
   case tok::kw_double:
   case tok::kw_void: